If you ordered cPanel license for your VPS, you may need to reinstall the OS via our VPSManager (vpsmanager.quickweb.co.nz) look for "Reinstall" icon and select CentOS 5.5 WHM/cPanel template, wait for about 10 minutes for the OS to be fully rebuilt and it should be readily accessible from  http://yourip:2086/
cPanel automatically activate your trial license so you can immediately use software while we are processing/obtaining your license from our supplier, this normally takes 1-3 business days. but you don't have to worry because the trial can last from 15-45 days and it is fully functional. This is better than waiting for your license be issued before you can work on your server.
Once we have activated your license you can remove the "trial" marking by running this command in your console (SSH)
If you are using XEN VPS we do not have pre-made cPanel OS template as of yet so you need to manually install cPanel from the command line see
http://docs.cpanel.net/twiki/bin/view/AllDocumentation/InstallationGuide/Quick-StartInstallationGuide